Rotating energy storage and conversion machines in the multi-megawatt range have been used to store and transfer power. Use of such energy storage and conversion machines has been limited to Scherbius-type electrical machines or direct current (DC) machines as used in railway kinetic energy storage devices. Both of these applications deal with slowly changing loads. Current energy storage and conversion machines with conventional inertial storage devices are not capable of supplying fast pulse power to loads. Additionally, current energy storage and conversion machines have not been developed to augment or utilize high-density battery charging.
Scherbius-type electrical machines for large scale energy storage applications are generally described in Rotating Converters for Interconnecting Power Systems, Brown Boveri Review, August 1964, which is incorporated by reference herein. A general overview of pulse forming networks is described in W. J. Sarjeant & R. E. Dollinger, High Power Electronics (TAB Books 1989), which is incorporated by reference herein. General cycloconverters, phase delay rectifiers, and alternating current (AC) link converters are described in B. R. Pelly, Thyristor Phase Controlled Converters and Cycloconverters, (John Wiley & Sons 1971), which is incorporated by reference herein. AC Link converters are described in U.S. Pat. Nos. 6,118,678 and 7,659,700, both of which are incorporated by reference herein.